Material for organic electroluminescence devices and organic electroluminescence device using the material

ABSTRACT

A material for organic electroluminescence devices comprising a compound in which a heterocyclic group having nitrogen is bonded to an arylcarbazolyl group or a carbazolylalkylene group and an organic electroluminescence device comprising an anode, a cathode and an organic thin film layer comprising at least one layer and disposed between the anode and the cathode, wherein at least one layer in the organic thin film layer comprises the material for organic electroluminescence devices described above. The material can provide an organic electroluminescence device emitting bluish light with a high purity of color. The organic electroluminescence device uses the material.

TECHNICAL FIELD

[0001] The present invention relates to a material for organicelectroluminescence devices (organic EL devices) and an organic ELdevice using the material and, more particularly, to an organic ELdevice emitting bluish light with a high purity of color.

BACKGROUND ART

[0002] Organic EL devices which utilize organic substances are expectedto be useful for application as an inexpensive full color display deviceof the solid light emission type having a great size and variousdevelopments on the organic EL devices are being conducted. In general,an organic EL device has a construction comprising a light emittinglayer and a pair of electrodes disposed at both sides of the lightemitting layer.

[0003] The light emission of the organic EL device is a phenomenon inwhich, when an electric field is applied between the two electrodes,electrons are injected from the cathode side and holes are injected fromthe anode side, the electrons are recombined with the holes in the lightemitting layer to form an excited state, and energy generated when theexcited state returns to the ground state is emitted as light.

[0004] As the light emitting material, chelate complexes such astris(8quinolinolato)aluminum, coumarine derivatives,tetraphenylbutadiene derivatives, bisstyrylarylene derivatives andoxadiazole derivatives are known. It has been reported that these lightemitting materials emit light in the visible region of blue to red andit is expected that color display devices can be obtained by using theselight emitting materials (for example, Japanese Patent ApplicationLaid-Open Nos. Heisei 8(1996)239655, Heisei 7(1995)-138561 and Heisei3(1991)-200289).

[0005] Although the practical use of displays using organic EL devicesrecently started, the full color display device is still underdevelopment. In particular, an organic EL device which emits bluishlight with excellent purity of color and efficiency of light emissionhas been desired.

[0006] As the device as the attempt to satisfy the above desire, forexample, a device using a phenylanthracene derivative as the materialemitting blue light is disclosed in Japanese Patent ApplicationLaid-Open No. Heisei 8(1996)-12600. The phenylanthracene derivative isused as the material emitting blue light and, in general, used as alaminate composed of a layer of the material emitting blue light and alayer of a complex of tris(8quinolinolato)aluminum (Alq). However, theefficiency of light emission, the life and the purity of blue light areinsufficient for the practical application. In Japanese PatentApplication Laid-Open No. 2001-288462, a device emitting blue light inwhich an amine-based aromatic compound is used for the light emittinglayer is disclosed. However, the efficiency of light emission of thisdevice is as insufficient as 2 to 4 cd/A. In Japanese Patent ApplicationLaid-Open No. 2001-160489, a device in which an azafluoranthene compoundis added to the light emitting layer is disclosed. However, this deviceemits light of yellow to green and cannot emit blue light having asufficiently high purity of color.

DISCLOSURE OF THE INVENTION

[0007] The present invention is made to overcome the above problems andhas an object of providing a material for organic EL devices which emitsbluish light with excellent purity of color and an organic EL deviceutilizing the material.

[0008] As the result of extensive studies by the present inventors, itwas found that an organic EL device exhibiting excellent purity of bluecolor could be obtained by using a compound having a heterocyclic grouphaving nitrogen bonded to an arylcarbazolyl group or acarbazolylalkylene group as the host material. The present invention hasbeen completed based on this knowledge.

[0009] The present invention provides a material for organicelectroluminescence devices which comprises a compound represented byfollowing general formula (1) or (2):

(Cz—)_(n)A   (1)

Cz(—A)_(m)  (2)

[0010] wherein Cz represents a substituted or unsubstitutedarylcarbazolyl group or carbazolylalkylene group, A represents a grouprepresented by following general formula (A):

(M)_(p)—(L)_(q)—(M′)_(r)  (A)

[0011] wherein M and M′ each independently represent a heteroaromaticring having 2 to 40 carbon atoms and nitrogen atom and forming asubstituted or unsubstituted ring, M and M′ may represent a same ring ordifferent rings, L represents a single bond, a substituted orunsubstituted aryl group or arylene group having 6 to 30 carbon atoms, asubstituted or unsubstituted cycloalkylene group having 5 to 30 carbonatoms or a substituted or unsubstituted heteroaromatic ring having 2 to30 carbon atoms, p represents an integer of 0 to 2, q represents aninteger of 1 or 2, r represents an integer of 0 to 2, and p+r representsan integer of 1 or greater; and n and m each represent an integer of 1to 3.

[0012] The present invention also provides an organicelectroluminescence device comprising an anode, a cathode and an organicthin film layer comprising at least one layer and disposed between theanode and the cathode, wherein at least one layer in the organic thinfilm layer comprises a material for organic electroluminescence devicesdescribed above. Among the above organic thin film layers, the lightemitting layer, the electron transporting layer or the hole transportinglayer may comprise the above material for organic EL devices.

THE MOST PREFERRED EMBODIMENT TO CARRY OUT THE INVENTION

[0013] The material for organic electroluminescence devices of thepresent invention comprises a compound represented by following generalformula (1) or (2):

(Cz—)_(n)A  (1)

Cz(—A)_(m)  (2)

[0014] In the above formulae, Cz represents a substituted orunsubstituted arylcarbazolyl group or carbazolylalkylene group and n andm each represent an integer of 1 to 3.

[0015] It is preferable that the aryl group in the arylcarbazolyl grouphas 6 to 30 carbon atoms. Examples of the aryl group include phenylgroup, naphthyl group, anthryl group, phenanthryl group, naphthacenylgroup, pyrenyl group, fluorenyl group, biphenyl group and terphenylgroup. Among these groups, phenyl group, naphthyl group, biphenyl groupand terphenyl group are preferable.

[0016] It is preferable that the alkylene group in thecarbazolylalkylene group has 1 to 10 carbon atoms. Examples of thealkylene group include methylene group, ethylene group, propylene group,isopropylene group, n-butylene group, s-butylene group, isobutylenegroup, t-butylene group, n-pentylene group, n-hexylene group,n-heptylene group, n-octylene group, hydroxymethylene group,chloromethylene group and aminomethylene group. Among these groups,methylene group, ethylene group, propylene group, isopropylene group,n-butylene group, t-butylene group and n-pentylene group are preferable.

[0017] In general formulae (1) and (2), A represents a group representedby the following general formula (A):

(M)_(p)—(L)_(q)—(M′)_(r)  (A)

[0018] M and M′ each independently represent a heteroaromatic ringhaving 2 to 40 carbon atoms and nitrogen atom and forming a substitutedor unsubstituted ring, and M and M′ may represent the same ring ordifferent rings.

[0019] Examples of the heteroaromatic ring having nitrogen atom includerings of pyridine, pyrimidine, pyrazine, triazine, aziridine,azaindolidine, indolidine, imidazole, indole, isoindole, indazole,purine, puteridine, β-carboline, naphthylidine, quinoxaline,terpyridine, bipyridine, acridine, phenanthroline, phenazine andimidazopyridine. Among these rings, rings of pyridine, terpyridine,pyrimidine, imidazopyridine and triazine are preferable.

[0020] L represents a single bond, a substituted or unsubstituted arylgroup or arylene group having 6 to 30 carbon atoms, a substituted orunsubstituted cycloalkylene group having 5 to 30 carbon atoms or asubstituted or unsubstituted heteroaromatic ring having 2 to 30 carbonatoms.

[0021] p represents an integer of 0 to 2, q represents an integer of 1or 2, r represents an integer of 0 to 2, and p+r represents an integerof 1 or greater.

[0022] Examples of the aryl group having 6 to 30 carbon atoms includephenyl group, biphenyl group, terphenyl group, naphthyl group, anthranylgroup, phenanthryl group, pyrenyl group, chrysenyl group, fluoranthenylgroup and perfluoroaryl groups. Among these groups, phenyl group,biphenyl groups, terphenyl group and perfluoroaryl groups arepreferable.

[0023] Examples of the arylene group having 6 to 30 carbon atoms includephenylene group, biphenylene group, terphenylene group, naphthylenegroup, anthranylene group, phenanthrylene group, pyrenylene group,chrysenylene group, fluoranthenylene group and perfluroarylene groups.Among these groups, phenylene group, biphenylene group, terphenylenegroup and perfluoroarylene groups are preferable.

[0024] Examples of the cycloalkylene group having 5 to 30 carbon atomsinclude cyclopentylene group, cyclohexylene group and cycloheptylenegroup. Among these groups, cyclohexylene group is preferable.

[0025] Examples of the heteroaromatic group having 2 to 30 carbon atomsinclude 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyradinylgroup, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group,1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group,5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxanyl group, 5-quinoxanyl group,6-quinoxanyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolylgroup, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthrydinyl group,2-phenanthrydinyl group, 3-phenanthrydinyl group, 4-phenanthrydinylgroup, 6-phenanthrydinyl group, 7-phenanthrydinyl group,8phenanthrydinyl group, 9-phenanthrydinyl group, 10-phenanthrydinylgroup, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group,4-acridinyl group, 9-acridinyl group, 1,7-phenanthrolin-2-yl group,1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group,1,7-phenanthrolin-5-yl group, 1,7-phenanthrolin-6-yl group,1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group,1,7-phenanthrolin-10-yl group, 1,8-phenanthrolin-2-yl group,1,8-phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group,1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group,1,8-phenanthrolin-7-yl group, 1,8-phenanthrolin-9-yl group,1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group,1,9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group,1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group,1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group,1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl group,1,10-phenanthrolin-3-yl group, 1,10-phenanthrolin-4-yl group,1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group,2,9-phenanthrolin-3-yl group, 2,9-phenanthrolin-4-yl group,2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group,2,9-phenanthrolin-7-yl group, 2,9-phenanthrolin-8-yl group,2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group,2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group,2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group,2,8-phenanthrolin-7-yl group, 2,8-phenanthrolin-9-yl group,2,8-phenanthrolin-10-yl group, 2,7-phenanthrolin-1-yl group,2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group,2,7-phenanthrolin-5-yl group, 2,7-phenanthrolin-6-yl group,2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group,2,7-phenanthrolin-10-yl group, 1-phenoxazinyl group, 2-phenoxazinylgroup, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinylgroup, 4-phenothiazinyl group, 10-phenothiazinyl group, 1-phenoxazinylgroup, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group,10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolylgroup, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group,2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2methylpyrrol-5-ylgroup, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group,3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group,2-tbutylpyrrol-4-yl group, 3-(2-phenylpropyl)pyrrol- 1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group and4-t-butyl-3-indolyl group. Among these groups, pyridinyl group andquinolyl group are preferable.

[0026] Examples of the substituent in the group represented by Cz, M orM′ in general formulae (1), (2) and (A) include halogen atoms such aschlorine atom, bromine atom and fluorine atom, carbazole group, hydroxylgroup, substituted and unsubstituted amino groups, nitro group, cyanogroup, silyl group, trifluoromethyl group, carbonyl group, carboxylgroup, substituted and unsubstituted alkyl groups, substituted andunsubstituted alkenyl groups, substituted and unsubstituted arylalkylgroups, substituted and unsubstituted aromatic groups, substituted andunsubstituted heteroaromatic heterocyclic groups, substituted andunsubstituted aralkyl groups, substituted and unsubstituted aryloxygroups and substituted and unsubstituted alkyloxyl groups. Among thesegroups, fluorine atom, methyl group, perfluorophenylene group, phenylgroup, naphthyl group, pyridyl group, pyrazyl group, pyrimidyl group,adamantyl group, benzyl group, cyano group and silyl group arepreferable.

[0027] The bonding mode of the compound represented by general formula(1) or (2) described above is shown in Table 1 in the following inaccordance with the numbers represented by n and m. TABLE 1 n = m = 1 n= 2 n = 3 m = 2 m = 3 Cz-A Cz-A-Cz

A-Cz-A

[0028] The bonding mode of the group represented by general formula (A)described above is shown in Table 2 in the following in accordance withthe numbers represented by p, q and r. TABLE 2 No p q r The bonding mode [1] 0 1 1 L-M′  [2] 0 1 2 L-M′-M′, M′-L-M′  [3] 0 2 1 L-L-M′, L-M′-L [4] 0 2 2

 [5] 1 1 0 The same as [1] except that M′ is replaced with M.  [6] 1 1 1M-L-M′  [7] 1 1 2

 [8] 1 2 0 The same as [3] except that M′ is replaced with M.  [9] 1 2 1M-L-L-M′, L-M-L-M′, M-L-M′-L [10] 1 2 2

[11] 2 1 0 The same as [2] except that M′ is replaced with M. [12] 2 1 1The same as [7] except that M′ is replaced with M and M is replaced withM′. [13] 2 1 2

[14] 2 2 0 The same as [4] except that M′ is replaced with M. [15] 2 2 1The same as [10] except that M′ is replaced with M and M is replacedwith M′. [16] 2 2 2

[0029] The group represented by Cz which is bonded to the grouprepresented by A may be bonded to any of the groups represented by M, Lor M′ in general formula (A) representing the group represented by A.

[0030] For example, when the group represented by A has the bonding mode[6] in Table 2 (p=q=r=1) in the compound represented by Cz—A in whichm=n=1 in general formula (1) or (2), the bonding mode includes threebonding modes of Cz—M—L—M′, M—L(Cz)—M′ and M—L—M′—Cz.

[0031] When the group represented by A has the bonding mode [7] in Table2 (p=q=1 and r=2) in the compound represented by Cz—A—Cz in which n=2 ingeneral formula (1), the bonding mode includes bonding modes shown inthe following:

[0032] With respect to the bonding mode of the group represented bygeneral formula (1), (2) or (A) and the combination of the groups shownin the above as the examples, materials for organic EL devicescomprising compounds shown in (i) to (iv) in the following arepreferable. ps (i) Materials For Organic EL Devices in Which

[0033] n=1 in general formula (1) and p=1 and r=0 in general formula(A);

[0034] in general formula (1), Cz represents a substituted orunsubstituted arylcarbazolyl group or carbazolylalkylene group; and

[0035] in general formula (A), M represents a heterocyclic six-memberedor seven-membered ring having 4 or 5 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring, a heterocyclicfive-membered ring having 2 to 4 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring, a heterocyclic ring having8 to 11 carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring or a substituted or unsubstituted imidazopyridinylring, and L represents a substituted or unsubstituted aryl group orarylene group having 6 to 30 carbon atoms or a substituted orunsubstituted heteroaromatic ring having 2 to 30 carbon atoms.

[0036] (ii) Materials For Organic EL Devices in Which

[0037] n=2 in general formula (1) and p=1 and r=0 in general formula(A);

[0038] in general formula (1), Cz represents a substituted orunsubstituted arylcarbazolyl group or carbazolylalkylene group; and

[0039] in general formula (A), M represents a heterocyclic six-memberedor seven-membered ring having 4 or 5 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring, a heterocyclicfive-membered ring having 2 to 4 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring, a heterocyclic ring having8 to 11 carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring or a substituted or unsubstituted imidazopyridinylring, and L represents a substituted or unsubstituted aryl group orarylene group having 6 to 30 carbon atoms or a substituted orunsubstituted heteroaromatic ring having 2 to 30 carbon atoms.

[0040] (iii) Materials For Organic EL Devices in Which

[0041] n=1 in general formula (1) and p=2 and r=0 in general formula(A);

[0042] in general formula (1), Cz represents a substituted orunsubstituted arylcarbazolyl group or carbazolylalkylene group; and

[0043] in general formula (A), M represents a heteroaromatic ring having2 to 40 carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring, and L represents a substituted or unsubstituted arylgroup or arylene group having 6 to 30 carbon atoms or a substituted orunsubstituted heteroaromatic ring having 2 to 30 carbon atoms.

[0044] (iv) Materials For Organic EL Devices in Which

[0045] m=2 in general formula (2) and p=q=1 in general formula (A);

[0046] in general formula (2), Cz represents a substituted orunsubstituted arylcarbazolyl group or carbazolylalkylene group; and

[0047] in general formula (A), M and M′ each independently represent aheteroaromatic ring having 2 to 40 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring, and M and M′ may representa same ring or different rings, and L represents a substituted orunsubstituted aryl group or arylene group having 6 to 30 carbon atoms, asubstituted or unsubstituted cycloalkylene group having 5 to 30 carbonatoms or a substituted or unsubstituted heteroaromatic ring having 2 to30 carbon atoms.

[0048] In the above general formulae (1) and (2), it is preferable thatCz represents a substituted or unsubstituted arylcarbazolyl group and,more preferably, phenylcarbazolyl group. It is preferable that the arylportion of the arylcarbazolyl group is substituted with carbazolylgroup.

[0049] Specific examples of the compound represented by general formula(1) are shown in the following. However, the compound represented bygeneral formula (1) is not limited to these compounds.

[0050] Specific examples of the compound represented by general formula(2) are shown in the following. However, the compound represented bygeneral formula (2) is not limited to these compounds.

[0051] It is preferable that the energy gap of the triplet state of acompound represented by general formula (1) or (2) is 2.5 to 3.3 eV andmore preferably 2.5 to 3.2 eV. It is preferable that the energy gap ofthe singlet state of a compound represented by general formula (1) or(2) is 2.8 to 3.8 eV and more preferably 2.9 to 3.7 eV.

[0052] The organic EL device of the present invention comprises ananode, a cathode and an organic thin film layer comprising at least onelayer disposed between the anode and the cathode, wherein at least onelayer in the organic thin film layer comprises the material for organicelectroluminescence devices comprising the compound represented by theabove general formula (1) or (2).

[0053] It is preferable that the organic EL device of the presentinvention comprises the material for organic electroluminescence devicescomprising the compounds represented by the above general formula (1) or(2) in the light emitting layer, the electron transporting layer or thehole transporting layer.

[0054] The organic EL device of the present invention emits bluish lightand the purity of color of the emitted light is as excellent as (0.12,0.10) to (0.17, 0.20). This property is exhibited since the material fororganic EL devices comprising the compound represented by generalformula (1) or (2) of the present invention has a great energy gap.

[0055] It is preferable that the organic EL device of the presentinvention emits light by a multiplet excitation which is the excitationto the triplet state or higher.

[0056] It is preferable that the material for organicelectroluminescence devices is a host material of the organic EL device.The host material is a material into which holes and electrons can beinjected and which has the function of transporting holes and electronsand emitting fluorescent light by recombination of holes and electrons.

[0057] The compounds represented by general formulae (1) and (2) in thepresent invention are useful also as the organic host material forphosphorescence devices since the energy gap of the singlet state is ashigh as 2.8 to 3.8 eV and the energy gap of the triplet state is as highas 2.5 to 3.3 eV.

[0058] The phosphorescence device is the organic device which comprisesa substance emitting light based on the transition from the energy levelof the triplet state to the energy level of the ground singlet statewith a stronger intensity than those emitted from other substances,i.e., a phosphorescent material such as organometallic complexescomprising at least one metal selected from Groups 7 to 11 of thePeriodic Table, and emits light under an electric field utilizing theso-called phosphorescence.

[0059] In the light emitting layer of the organic EL device, in general,the singlet exciton and the triplet exciton are mixed in the formedexcited molecules and it is said that the ratio of the amount of thesinglet exciton to the amount of the triplet exciton is 1:3 and thetriplet exciton is formed in a greater amount. In conventional organicEL devices using the phosphorescence, the exciton contributing to thelight emission is the singlet exciton and the triplet exciton does notemit light. Therefore, the triplet exciton is ultimately consumed asheat and the light is emitted by the singlet exciton which is formed ina smaller amount. Therefore, in these organic EL devices, the energytransferred to the triplet exciton in the energy generated by therecombination of holes and electrons causes a great loss.

[0060] In contrast, it is considered that, by using the compound of thepresent invention for the phosphorescence device, the efficiency oflight emission three times as great as that of a device using afluorescence can be obtained since the triplet exciton can be used foremission of light. It is also considered that, when the compound of thepresent invention is used for the light emitting layer of thephosphorescence device, an excited triplet state having an energy statehigher than the excited triplet state of a phosphorescent organometalliccomplex comprising a metal selected from the Group 7 to 11 of thePeriodic Table is formed; the film having a more stable form is formed;the glass transition temperature is higher (Tg: 80 to 160° C.); theholes and the electrons are efficiently transported; the compound iselectrochemically and chemically stable; and the formation of impuritieswhich may work as a trap or causes the loss in the light emission issuppressed during the preparation and the use.

[0061] The organic EL device of the present invention comprises, asdescribed above, one or more organic thin film layers formed between theanode and the cathode. When the device comprises a single layer, a lightemitting layer is formed between the anode and the cathode. The lightemitting layer comprises a light emitting material and, further, a holeinjecting material for transporting holes injected from the anode to thelight emitting material or an electron injecting material fortransporting electrons injected from the cathode to the light emittingmaterial. It is preferable that the light emitting material exhibits avery excellent phosphorescent quantum efficiency, has a great ability oftransporting both holes and electrons and forms a uniform thin layer.Examples of the organic EL device of the multi-layer type includeorganic EL device comprising a laminate having a multi-layerconstruction such as (the anode/the hole injecting layer/the lightemitting layer/the cathode), (the anode/the light emitting layer/theelectron injecting layer/the cathode) and (the anode/the hole injectinglayer/the light emitting layer/the electron injecting layer).

[0062] For the light emitting layer, in addition to the compoundrepresented by general formula (1) or (2) of the present invention,conventional host materials, light emitting materials, doping materials,hole injecting materials and electron injecting materials andcombinations of these materials may be used, where necessary. By using amulti-layer structure for the organic EL device, decreases in theluminance and the life due to quenching can be prevented and theluminance of emitted light and the efficiency of light emission can beimproved with other doping materials. By using other doping materialscontributing to the light emission of the phosphorescence incombination, the luminance of emitted light and the efficiency of lightemission can be improved in comparison with conventional devices.

[0063] In the organic EL device of the present invention, the holeinjecting layer, the light emitting layer and the electron injectinglayer may each have a multi-layer structure. When the hole injectinglayer has a multilayer structure, the layer into which holes areinjected from the electrode is called the hole injecting layer and thelayer which receives holes from the hole injecting layer and transportsholes to the light emitting layer is called the hole transporting layer.Similarly, when the electron injecting layer has a multi-layerstructure, the layer into which electron are injected from the electrodeis called the electron injecting layer and the layer which receiveselectrons from the electron injecting layer and transports electrons tothe light emitting layer is called the electron transporting layer. Thelayers are selected in accordance with the energy levels of thematerial, heat resistance and adhesion with the organic thin film layersor the metal electrodes.

[0064] In the organic EL device of the present invention, the electrontransporting layer and/or the hole transporting layer may comprise thematerial for organic EL devices of the present invention which comprisesany of the compounds represented by general formulae (1) and (2). Thehole injecting layer, the electron injecting layer and the hole barrierlayer may comprise the material for organic EL devices of the presentinvention. A phosphorescent light emitting compound and the material fororganic EL materials of the present invention may be used as a mixture.

[0065] Examples of the light emitting material and the host materialwhich can be used for the organic thin film layer in combination withthe compound represented by general formula (1) or (2) includeanthracene, naphthalene, phenanthrene, pyrene, tetracene, coronen,chrysene, fluoresceine, perylene, phthaloperylene, naphthaloperylene,perynone, phthaloperynone, naphthaloperynone, diphenylbutadiene,tetraphenylbutadiene, coumarine, oxadiazole, aldazine, bisbenzoxazoline,bisstyryl, pyrazine, cyclopentadiene, metal complexes of quinoline,metal complexes of aminoquinoline, metal complexes of benzoquinoline,imines, diphenylethylene, vinylanthracene, diaminoanthracene,diaminocarbazole, pyrane, thiopyrane, polymethine, melocyanine, oxinoidcompounds chelated with imidazole, quinacridone, rubrene, stilbene-basedderivatives and phosphorescent pigments. However, the light emittingmaterial and the host material are not limited to the compoundsdescribed above.

[0066] As the light emitting material, phosphorescent organometalliccomplexes are preferable since the external quantum efficiency of thedevice can be improved. Examples of the metal in the phosphorescentorganometallic complex include ruthenium, rhodium, palladium, silver,rhenium, osmium, iridium, platinum and gold. It is preferable that theorganometallic complex is an organometallic compound represented by thefollowing general formula (3):

[0067] In the above general formula, Al represents a substituted orunsubstituted aromatic hydrocarbon cyclic group or aromatic heterocyclicgroup which is preferably phenyl group, biphenyl group, naphthyl group,anthryl group, thienyl group, pyridyl group, quinolyl group orisoquinolyl group. Examples of the substituent include halogen atomssuch as fluorine atom; alkyl groups having 1 to 30 carbon atoms such asmethyl group and ethyl group; alkenyl groups such as vinyl group;alkoxycarbonyl groups having 1 to 30 carbon atoms such asmethoxycarbonyl group and ethoxycarbonyl group; alkoxyl groups having 1to 30 carbon atoms such as methoxy group and ethoxyl group; aryloxygroups such as phenoxyl group and benzyloxyl group; dialkylamino groupssuch as dimethylamino group and diethylamino group; acyl groups such asacetyl group; haloalkyl groups such as trifluoromethyl group; and cyanogroup.

[0068] A² represents a substituted or unsubstituted aromaticheterocyclic group having nitrogen atom as the atom forming theheterocyclic ring, which is preferably pyridyl group, pirimidyl group,pyrazine group, triazine group, benzothiazole group, benzoxazole group,benzimidazole group, quinolyl group, isoquinolyl group, quinoxalinegroup or phenanthridine group. Examples of the substituent include thesubstituents described as the examples of the substituent for the grouprepresented by A¹.

[0069] The ring having the group represented by A¹ and the ring havingthe group represented by A² may form one condensed ring. Examples of thecondensed ring include 7,8-benzoquinoline group.

[0070] Q represents a metal selected from metals of Groups 7 to 11 ofthe Periodic Table, which is preferably ruthenium, rhodium, palladium,silver, rhenium, osmium, iridium, platinum or gold.

[0071] L represents a bidentate ligand, which is preferably selectedfrom ligands of the β-diketone type such as acetylacetonates andpyromellitic acid.

[0072] m and n each represent an integer. When Q represents a divalentmetal, n=2 and m=0. When Q represents a trivalent metal, n=3 and m=0 orn=2 and m=1.

[0073] Specific examples of the organometallic complex represented bythe above general formula (3) are shown in the following. However, theorganometallic complex is not limited to these compounds.

[0074] As the hole injecting material, compounds which have the abilityto transport holes, exhibits the excellent effect of receiving holesinjected from the anode and the excellent effect of injecting holes tothe light emitting layer or the light emitting material, preventstransfer of excitons formed in the light emitting layer to the electroninjecting layer or the electron injecting material and has the excellentability of forming a thin film, are preferable. Examples of the holeinjecting compound include phthalocyanine derivatives, naphthalocyaninederivatives, porphyrin derivatives, oxazoles, oxadiazoles, triazoles,imidazoles, imidazolones, imidazolethiones, pyrazolines, pyrazolones,tetrahydroimidazoles, hydrazones, acylhydrazones, polyarylalkanes,stilbene, butadiene, triphenylamine of the benzidine type,triphenylamine of the styrylamine type, triphenylamine of the diaminetype, derivatives of the above compounds and macromolecular materialssuch as polyvinyl-carbazoles, polysilanes and electrically conductivemacromolecules. However, the hole injecting material is not limited tothese materials.

[0075] Among these hole injecting materials, the more effective holeinjecting materials are aromatic tertiary amine derivatives andphthalocyanine derivatives. Examples of the aromatic tertiary aminederivative include triphenylamine, tritolylamine, tolyldiphenylamine,N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine,N,N,N′,N′-(4-methylphenyl)-1,1′-phenyl-4,4′-diamine,N,N,N′,N′-(4-methylphenyl)-1,1′-biphenyl-4,4′-diamine,N,N′-diphenyl-N,N′-dinaphthyl-1,1′-biphenyl-4,4′-diamine,N,N′-(methylphenyl)-N,N′-(4-n-butylphenyl)-phenanthrene-9,10-diamine,N,N-bis(4-di-4-tolylaminophenyl)-4-phenylcyclohexane and oligomers andpolymers having the skeleton structure of these aromatic tertiaryamines. However, the aromatic tertiary amine is not limited to thesecompounds. Examples of the phthalocyanine (Pc) derivative includephthalocyanine derivatives and naphthalocyanine derivatives such asH₂Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc,ClSnPc, Cl₂SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc and GaPc—O—GaPc.However the phthalocyanine derivative is not limited to these compounds.

[0076] As the electron injecting material, compounds which have theability to transport electrons, exhibits the excellent effect ofreceiving electrons injected from the anode and the excellent effect ofinjecting electrons to the light emitting layer or the light emittingmaterial, prevents transfer of excitons formed in the light emittinglayer to the hole injecting layer and has the excellent ability offorming a thin film, are preferable. Examples of the electron injectingcompound include fluorenone, anthraquinodimethane, diphenoquinone,thiopyrane dioxide, oxazoles, oxadiazoles, triazoles, imidazoles,perylenetetracarboxylic acid, quinoxaline, fluorenylidenemethane,anthraquinodimethane, anthrone and derivatives of these compounds.However, the electron injecting material is not limited to thesecompounds.

[0077] Among these electron injecting materials, the more effectiveelectron injecting materials are metal complex compounds andfive-membered derivatives having nitrogen. Examples of the metal complexcompound include 8-hydroxyquinolinatolithium,bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper,bis(8-hydroxyquinolinato)manganese, tris(8-hydroxyquinolinato)aluminum,tris(2methyl-8-hydroxyquinolinato)aluminum, tris(8-hydroxyquinolinato)-gallium,bis(10-hydroxybenzo[h]quinolinato)beryllium,bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2- methyl-8-quinolinato)chlorogallium,bis(2methyl-8-quinolinato)(o-cresolato)gallium,bis(2-methyl-8-quinolinato) (1naphtholato)aluminum andbis(2-methyl-8-quinolinato)(2-naphtholato)-gallium. However the electroninjecting material is not limited to these compounds.

[0078] As the five-membered derivative having nitrogen, oxazoles,thiazoles, oxadiazoles, thiadiazoles, triazoles and derivatives of thesecompounds are preferable. Examples of the five-membered derivativehaving nitrogen include bis(1-phenyl)-1,3,4-oxazole, dimethylPOPOP,2,5bis(1-phenyl)-1,3,4-thiazole, 2,5-bis(1-phenyl)-1,3,4-oxadiazole,2-(4′-tertbutylphenyl)-5-(4″-biphenyl)-1,3,5-oxadiazole,2,5-bis(1-naphthyl)-1,3,4-oxadiazole,1,4-bis[2-(5-phenyloxadiazolyl)]benzene, 1 ,4-bis[2-(5-phenyloxadiazolyl)-4-tert-butylbenzene],2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-thiadiazole,2,5-bis(1-naphthyl)-1,3,4-thiadiazole,1,4-bis[2-(5-phenylthiadiazolyl)]benzene, 2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-triazole,2,5-bis(1-naphthyl)-1,3,4-triazole and1,4-bis[2-(5-phenyltriazolyl)]benzene. However, the five-memberedderivative having nitrogen is not limited to these compounds.

[0079] The property of charge injection can be improved by adding anelectron-accepting compound to the hole injecting material and anelectron-donating compound to the electron injecting material.

[0080] As the electrically conductive material used for the anode of theorganic EL device of the present invention, a material having a workfunction greater than 4 eV is suitable and carbon, aluminum, vanadium,iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium,alloys of these metals, metal oxides such as tin oxides and indium oxideused for ITO substrates and NESA substrates and organic electricallyconductive resins such as polythiophene and polypyrrol are used. As theelectrically conductive material used for the cathode, a material havinga work function smaller than 4 eV is suitable and magnesium, calcium,tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminumand alloys of these metals are used. However, the electricallyconductive material used for the cathode is not limited to thesematerials. Typical examples of the alloy include magnesium/silver,magnesium/indium and lithium/aluminum. However, the alloy is not limitedto these alloys. The composition of the alloy is controlled by thetemperature of the source of vaporization, the atmosphere and the degreeof vacuum and a suitable composition is selected. The anode and thecathode may be formed with a structure having two or more layers, wherenecessary.

[0081] The organic EL device of the present invention may comprise aninorganic compound layer between at least one of the electrodes and theabove organic thin film layer. Examples of the inorganic compound usedfor the inorganic compound layer include various types of oxides,nitrides and oxide nitrides such as alkali metal oxides, alkaline earthmetal oxides, rare earth oxides, alkali metal halides, alkaline earthmetal halides, rare earth halides, SiO_(x), AlO_(x), SiN_(x), SiON,AlON, GeO_(x), LiO_(x), LiON, TiO_(x), TiON, TaO_(x), TaON, TaN_(x) andC. In particular, as the component contacting the anode, SiO_(x),AlO_(x), SiN_(x), SiON, AlON, GeO_(x) and C are preferable since astable interface layer of injection is formed. As the componentcontacting the cathode, LiF, MgF₂, CaF₂ and NaF are preferable.

[0082] In the organic EL device of the present invention, it ispreferable that at least one face is sufficiently transparent in theregion of the wavelength of the light emitted by the device so that thelight emission is achieved efficiently. It is preferable that thesubstrate is also transparent.

[0083] For the transparent electrode, the conditions in the vapordeposition or the sputtering are set so that the prescribed transparencyis surely obtained using the above electrically conductive material. Itis preferable that the electrode of the light emitting face has atransmittance of light of 10% or greater. The substrate is notparticularly limited as long as the substrate has the mechanical andthermal strength and is transparent. Examples of the substrate includeglass substrates and transparent films of resins. Examples of thetransparent film of a resin include films of polyethylene,ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers,polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinylalcohol, polyvinyl butyral, nylon, polyether ether ketones,polysulfones, polyether sulfones, tetrafluoroethylene-perfluoroalkylvinyl ether copolymers, polyvinyl fluoride,tetrafluoro-ethylene-ethylene copolymers,tetrafluoroethylene-hexafluoropropylene copolymers,polychlorotrifluoroethylene, polyvinylidene fluoride, polyesters,polycarbonates, polyurethanes, polyether imides, polyimides andpolypropylene.

[0084] In the organic EL device of the present invention, it is possiblethat a protective layer is formed on the surface of the device or theentire device is covered with a silicone oil or a resin so thatstability to the temperature, the humidity and the atmosphere isimproved.

[0085] For the formation of each layer of the organic EL device of thepresent invention, any of the dry processes of film formation such asthe vacuum vapor deposition, the sputtering, the plasma plating and theion plating and the wet processes of film formation such as the spincoating, the dipping and the flow coating, can be applied. The thicknessof each film is not particularly limited. However, it is necessary thatthe thickness of the film be set at a suitable value. When the thicknessis excessively great, application of a greater voltage is necessary toobtain the same output of the light and the efficiency of light emissiondecreases. When the thickness is excessively small, pin holes are formedand sufficient light emission cannot be obtained even when an electricfield is applied. In general, a thickness in the range of 5 nm to 10 μmis suitable and a thickness in the range of 10 nm to 0.2 μm ispreferable.

[0086] When the wet process of film formation is used, the materialforming each layer is dissolved or suspended in a suitable solvent suchas ethanol, chloroform, tetrahydrofuran and dioxane and a thin film isformed from the obtained solution or suspension. Any of the abovesolvents can be used. For any of the layers, suitable resins andadditives may be used to improve the property for film formation and toprevent formation of pin holes in the film. Examples of the resin whichcan be used include insulating resins such as polystyrene,polycarbonates, polyarylates, polyesters, polyamides, polyurethanes,polysulfones, polymethyl methacrylate, polymethyl acrylate, celluloseand copolymers of these resins; photoconductive resins such aspoly-N-vinylcarbazole and polysilanes; and electrically conductiveresins such as polythiophene and polypyrrol. Examples of the additiveinclude antioxidants, ultraviolet light absorbents and plasticizers.

[0087] As described above, by using the compound represented by generalformula (1) or (2) for the organic thin film layer of the organic ELdevice of the present invention, the organic EL device emitting bluelight with a high purity of color can be obtained. This organic ELdevice can be advantageously used for a photosensitive member forelectronic photograph, a planar light emitting member such as a flatpanel display of wall televisions, a back light of copiers, printers andliquid crystal displays, a light source for instruments, a displaypanel, a marking light and an accessory.

[0088] The present invention will be described more specifically withreference to examples in the following. However, the present inventionis not limited to the examples.

[0089] The triplet energy gap and the singlet energy gap of a compoundwere measured in accordance with the following methods.

[0090] (1) Measurement of the Triplet Energy Gap

[0091] The lowest excited triplet energy level T1 was measured. Thephosphorescence spectrum of a sample was measured (10 μmoles/liter; anEPA (diethyl ether: isopentane : ethanol=5:5:2 by volume) solution; 77K;a quartz cell; FLUOROLOG II manufactured by SPEX Company). A tangent wasdrawn to the increasing line at the short wavelength side of thephosphorescence spectrum and the wavelength at the intersection of thetangent and the abscissa (the end of light emission) was obtained. Theobtained wavelength was converted into the energy.

[0092] (2) Measurement of the Singlet Energy Gap

[0093] The excited singlet energy gap was measured. Using a toluenesolution (10⁻⁵ moles/liter) of a sample, the absorption spectrum wasobtained by a spectrometer for absorption of ultraviolet and visiblelight manufactured by HITACHI Co. Ltd. A tangent was drawn to theincreasing line at the long wavelength side of the spectrum and thewavelength at the intersection of the tangent and the abscissa (the endof absorption) was obtained. The obtained wavelength was converted intothe energy.

SYNTHESIS EXAMPLE 1 (Synthesis of Compound (A5))

[0094] The route of synthesis of Compound (A5) is shown in thefollowing.

[0095] (1) Synthesis of Intermediate Compound (A)

[0096] 2,4′-Dibromoacetophenone in an amount of 15 g (54 mmoles) wasdissolved into 100 ml of ethanol. To the obtained solution, 7.0 g ofsodium hydrogencarbonate and 5.2 g (55 mmoles) of 2-aminopyridine wereadded and the resultant mixture was heated for 9 hours under therefluxing condition. After the reaction was completed, the mixture wascooled at the room temperature. The formed crystals were separated byfiltration and washed with water and ethanol and 12.5 g (the yield: 85%)of Intermediate Compound (A) was obtained.

[0097] (2) Synthesis of Compound (A5)

[0098] Into a reactor, 6.1 g (19 mmoles) of 3,6-diphenylcarbazole, 6.3 g(23 mmoles) of Intermediate Compound (A), 0.2 g of copper powder, 1.7 gof 18-crown-6 and 2.9 g (21 mmoles) of potassium carbonate were placedand 30 ml of o-dichlorobenzene was added as the solvent. The resultantmixture was heated at 200° C. in a silicone oil bath under a nitrogenstream and the reaction was allowed to proceed for 48 hours. After thereaction was completed, the reaction mixture was filtered under suctionbefore being cooled and the obtained filtrate was concentrated using anevaporator. To the obtained oily product, 30 ml of methanol was added.The formed solid substance was separated by filtration under a reducedpressure and a gray solid substance was obtained. The obtained solidsubstance was recrystallized from benzene and 3.0 g (the yield: 31%) ofwhite crystals were obtained. It was confirmed by 90 MHz ¹H-NMR andFD-MS (the field desorption mass analysis) that the obtained crystalswere the target substance (A5). The result of the measurement by FD-MSis shown in the following:

[0099] FD-MS calcd. for C₃₇H₂₅N₃=511; found: m/z=511(M⁺, 100)

[0100] The values of the energy gaps were obtained in accordance withthe methods described above and the results are shown in Table 3.

SYNTHESIS EXAMPLE 2 (Synthesis of Compound (A3))

[0101] The route of synthesis of Compound (A3) is shown in thefollowing.

[0102] (1) Synthesis of Intermediate Compound (B)

[0103] 4-Bromobenzaldehyde in an amount of 15 g (81 mmoles) wasdissolved into 300 ml of ethanol. To the obtained solution, 10 g (83mmoles) of 2-acetylpyridine and 15 g (81 mmoles) of a 28% methanolsolution of sodium methoxide were added and the resultant mixture wasstirred at the room temperature for 7 hours. After the reaction wascompleted, the formed crystals were separated by filtration and washedwith ethanol and 9.5 g (the yield: 41%) of Intermediate Compound (B) wasobtained.

[0104] (2) Synthesis of Intermediate Compound (C)

[0105] Intermediate Compound (B) in an amount of 9.5 g (33 mmoles) wasdissolved into 80 ml of ethanol. To the obtained solution, 5.2 g (34mmoles) of benzamidine hydrochloride and 2.6 g (65 mmoles) of sodiumhydroxide were added and the resultant mixture was heated for 15 hoursunder the refluxing condition. After the reaction was completed, themixture was cooled at the room temperature. The formed crystals wereseparated by filtration and washed with water and ethanol and 3.46 g(the yield: 27%) of Intermediate Compound (C) was obtained.

[0106] (3) Synthesis of Compound (A3)

[0107] Into a reactor, 6.1 g (19 mmoles) of 3,6-diphenylcarbazole, 8.9 g(23 mmoles) of Intermediate Compound (C), 0.2 g of copper powder, 1.7 gof 8-crown-6 and 2.9 g (21 mmoles) of potassium carbonate were placedand 30 ml of o-dichlorobenzene was added as the solvent. The resultantmixture was heated at 200° C. in a silicone oil bath under a nitrogenstream and the reaction was allowed to proceed for 48 hours. After thereaction was completed, the reaction mixture was filtered under suctionbefore being cooled and the obtained filtrate was concentrated using anevaporator. To the obtained oily product, 30 ml of methanol was added.The formed solid substance was separated by filtration under a reducedpressure and a gray solid substance was obtained. The obtained solidsubstance was recrystallized from benzene and 3.9 g (the yield: 33%) ofwhite crystals were obtained. It was confirmed by 90 MHz ¹H-NMR andFD-MS that the obtained crystals were the target substance (A3). Theresult of the measurement by FD-MS is shown in the following:

[0108] FD-MS calcd. for C₄₅H₃₀N₄=626; found: m/z=626 (M⁺, 100)

[0109] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 3 (Synthesis of Compound (A26))

[0110] The route of synthesis of Compound (A26) is shown in thefollowing.

[0111] (1) Synthesis of Intermediate Compound (D)

[0112] Into a reactor, 33 g (0.20 moles) of carbazole, 68 g (0.24 moles)of p-bromoiodobenzene, 2.0 g of copper powder, 18 g of 18-crown-6 and 30g (0.22 moles) of potassium carbonate were placed and 300 ml ofo-dichlorobenzene was added as the solvent. The resultant mixture washeated at 200° C. in a silicone oil bath under a nitrogen stream and thereaction was allowed to proceed for 24 hours. After the reaction wascompleted, the reaction mixture was filtered under suction using aBuchner funnel before being cooled and the obtained filtrate wasconcentrated using an evaporator. To the obtained oily product, 30 ml ofmethanol was added. The formed solid substance was separated byfiltration under a reduced pressure and a gray solid substance wasobtained. The obtained solid substance was recrystallized from benzeneand 31 g (the yield: 49%) of white crystals were obtained.

[0113] (2) Synthesis of Compound (A26)

[0114] Into a reactor, 5.4 g (20 mmoles) of 2-biphenylindole, 7.7 g (24mmoles) of Intermediate Compound (D), 0.2 g of copper powder, 1.8 g of18-crown-6 and 3.0 g (22 mmoles) of potassium carbonate were placed and30 ml of o-dichlorobenzene was added as the solvent. The resultantmixture was heated at 200° C. in a silicone oil bath under a nitrogenstream and the reaction was allowed to proceed for 48 hours. After thereaction was completed, the reaction mixture was filtered under suctionbefore being cooled and the obtained filtrate was concentrated using anevaporator. To the obtained oily product, 30 ml of methanol was added.The formed solid substance was separated by filtration under a reducedpressure and a gray solid substance was obtained. The obtained solidsubstance was recrystallized from benzene and 1.7 g (the yield: 17%) ofwhite crystals were obtained. It was confirmed by 90 MHz ¹H-NMR andFD-MS that the obtained crystals were the target substance (A26). Theresult of the measurement by FD-MS is shown in the following:

[0115] FD-MS calcd. for C₃₈H₂₆N₂=510; found: m/z=510 (M⁺, 100)

[0116] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 4 (Synthesis of Compound (A27))

[0117] The route of synthesis of Compound (A27) is shown in thefollowing.

[0118] In accordance with the same procedures as those conducted inSynthesis Example 3 (2) except that 2-biphenyl-3-phenylindole was usedin place of 2-biphenylindole, 2.2 g (the yield: 19%) of white crystalswere obtained. It was confirmed by 90 MHz ¹H-NMR and FD-MS that theobtained crystals were the target substance (A27). The result of themeasurement by FD-MS is shown in the following:

[0119] FD-MS calcd. for C₄₄H₃₀N₂=586; found: m/z=586 (M⁺, 100)

[0120] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 5 (Synthesis of Compound (A11))

[0121] The route of synthesis of Compound (A11) is shown in thefollowing.

[0122] (1) Synthesis of Intermediate Compound (E)

[0123] 3,6-Biphenyl-9-p-bromophenylcarbazole in an amount of 7.6 g (16mmoles) was dissolved into 70 ml of ether. To the obtained solution, 12ml of a hexane solution (1.6 M) of n-butyllithium was added at −60° C.After the resultant solution was stirred at a temperature between −60°C. and 0° C. for 2 hours, the solution was cooled at −60° C. again and asolution obtained by diluting 8.8 g of triisopropyl borate with 10 ml ofether was added dropwise. After the resultant mixture was stirred at atemperature between −60° C. and 0° C. for 2 hours, the reaction wasquenched by adding a 5% aqueous solution of hydrochloric acid. Theformed crystals were separated by filtration and washed with water andmethanol and 4.0 g (the yield: 58%) of Intermediate Compound (E) wasobtained.

[0124] (2) Synthesis of Compound (A11)

[0125] 2-(4′-Bromophenyl)imidazo[1,2-a]pyridine in an amount of 2.0 g(7.3 mmoles), 3.5 g (8.0 mmoles) of Intermediate Compound (E), 0.2 g ofcopper powder and 0.17 g of tetrakis(triphenylphosphine)palladium weredissolved into 30 ml of 1,2-dimethoxyethane. To the resultant solution,12 ml of a 2.0 M aqueous solution of sodium carbonate was added and theobtained solution was heated for 8 hours under the refluxing condition.After the reaction was completed, the formed solid substance wasdissolved into dichloromethane, washed with water and dried with sodiumsulfate. After the solvent was removed by distillation, the obtainedproduct was washed with methanol and 2.0 g (the yield: 47%) of yellowishwhite solid substance was obtained. It was confirmed by 90 MHz ¹H-NMRand FD-MS that the obtained solid substance was the target substance(A11). The result of the measurement by FD-MS is shown in the following:FD-MS calcd. for C₄₃H₂₉N₃=587; found: m/z=587 (M⁺, 100)

[0126] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 6 (Synthesis of Compound (A9))

[0127] The route of synthesis of Compound (A9) is shown in thefollowing.

[0128] Intermediate Compound (C) obtained in Synthesis Example 2 in anamount of 2.0 g (5.2 mmoles), 1.7 g (5.8 mmoles) of4-(9′-carbazolyl)-phenylboric acid and 0.11 g oftetrakis(triphenylphosphine)palladium were dissolved into 20 ml of1,2-dimethoxyethane. To the resultant solution, 9 ml of a 2.0 M aqueoussolution of sodium carbonate was added and the obtained solution washeated for 8 hours under the refluxing condition. After the reaction wascompleted, the formed solid substance was dissolved intodichloromethane, washed with water and dried with sodium sulfate. Afterthe solvent was removed by distillation, the obtained product was washedwith methanol and 1.8 g (the yield: 62%) of yellowish white solidsubstance was obtained. It was confirmed by 90 MHz ¹H-NMR and FD-MS thatthe obtained solid substance was the target substance (A9). The resultof the measurement by FD-MS is shown in the following:

[0129] FD-MS calcd. for C₃₉H₂₆N₄=550; found: m/z=550 (M⁺, 100)

[0130] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 7 (Synthesis of Compound (A43))

[0131] The route of synthesis of Compound (A43) is shown in thefollowing.

[0132] Under a stream of argon, 2.33 g (10 mmoles) of2,3-dicyano-5-(pbromophenyl)-7-methyl-6H-1,4-diazepine, 2 g (12 mmoles)of carbazole, 0.14 g (1.5% by mole) oftris(dibenzylideneacetone)dipalladium, 0.06 g (3% by mole) oftri-t-butylphosphine, 2.0 g (22 mmoles) of sodium t-butoxide and 100 mlof dry toluene were placed into a 200 ml three-necked flask equippedwith a condenser and the resultant mixture was heated at 100° C. understirring for one night. After the reaction was completed, the formedcrystals were separated by filtration and washed with 100 ml of methanoland 1.2 g (3 mmoles) (the yield: 30%) of a light yellow powder wasobtained. It was confirmed by the measurements of NMR, IR and FD-MS thatthe obtained powder was the target substance (A43). The result of themeasurement by FD-MS is shown in the following:

[0133] FD-MS calcd. for C₂₆H₁₇N₅=399; found: m/z=399 (M⁺, 100)

SYNTHESIS EXAMPLE 8 (Synthesis of Compound (A45))

[0134] The route of synthesis of Compound (A45) is shown in thefollowing.

[0135] Under a stream of argon, 4.5 g (10 mmole) of2,3-dicyano-5,7-bis(pbromophenyl)-6H-1,4-diazepine, 4 g (24 mmoles) ofcarbazole, 0.28 g (1.5% by mole) oftris(dibenzylideneacetone)dipalladium, 0.12 g (3% by mole) oftri-t-butylphosphine, 4.2 g (442 mmoles) of sodium t-butoxide and 160 mlof dry toluene were placed into a 200 ml three-necked flask equippedwith a condenser and the resultant mixture was heated at 100° C. understirring for 18 hours. After the reaction was completed, the formedcrystals were separated by filtration and washed with 100 ml of methanoland 1.8 g (2.9 mmoles) (the yield: 29%) of a white powder was obtained.It was confirmed by the measurements of NMR, IR and FD-MS that theobtained powder was the target substance (A45). The result of themeasurement by FD-MS is shown in the following:

[0136] FD-MS calcd. for C₄₃H₂₆N₆=626; found: m/z=626 (M⁺, 100)

SYNTHESIS EXAMPLE 9 (Synthesis of Compound (B9))

[0137] The route of synthesis of Compound (B9) is shown in thefollowing.

[0138] Under the atmosphere of argon, 11 g (32 mmole, 2.6 eq) of4-(2′phenyl-4′-pyridylpirimidin-6′-yl)phenylboric acid, 5 g (12 mmoles)of 3,6-dibromo-9-phenylcarbazole and 0.55 g (0.48 mmoles, 2% Pd) oftetrakis(triphenylphosphine)palladium(0) were suspended in 100 ml of1,2-dimethoxyethane. To the resultant suspension, 10.2 g of a 2 Maqueous solution of sodium carbonate (96 mmoles, 3 eq/50 ml) was addedand the resultant mixture was heated for 10 hours under the refluxingcondition. After the organic layer was separated and concentrated, theproduct was purified in accordance with the column chromatography and8.5 g (the yield: 83%) of a white solid substance was obtained. It wasconfirmed by 90 MHz ¹H-NMR and FD-MS that the obtained solid substancewas the target substance (B9). The result of the measurement by FD-MS isshown in the following:

[0139] FD-MS calcd. for C₆₀H₃₉N₇=857; found: m/z=857 (M⁺, 100)

[0140] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 10 (Synthesis of Compound (B 1))

[0141] The route of synthesis of Compound (Bll) is shown in thefollowing.

[0142] Under the atmosphere of argon, 7.6 g (32 mmole, 2.6 eq) of4-(imidazopyridin-2′-yl)phenylboric acid, 5 g (12 mmoles) of3,6-dibromo-9-phenylcarbazole and 0.55 g (0.48 mmoles, 2% Pd) oftetrakis(triphenylphosphine)palladium(0) were suspended in 100 ml of1,2-dimethoxyethane. To the resultant suspension, 10.2 g of a 2 Maqueous solution of sodium carbonate (96 mmoles, 3 eq/50 ml) was addedand the resultant mixture was heated for 10 hours under the refluxingcondition. After the organic layer was separated and concentrated, theproduct was purified in accordance with the column chromatography and5.7 g (the yield: 76%) of a white solid substance was obtained. It wasconfirmed by 90 MHz ¹H-NMR and FD-MS that the obtained solid substancewas the target substance (B11). The result of the measurement by FD-MSis shown in the following:

[0143] FD-MS calcd. for C₄₄H₂₉N₅=627; found: m/z=627 (M⁺, 100)

[0144] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 11 (Synthesis of Compound (A72))

[0145] The route of synthesis of Compound (A72) is shown in thefollowing.

[0146] (1) Synthesis of Intermediate Compound (F)

[0147] In accordance with the same procedures as those conducted inSynthesis Example 2 (1) except that acetophenone was used in place of2-acetylpyridine, 29.4 g (the yield: 84%) of Intermediate Compound (F)was obtained.

[0148] (2) Synthesis of Intermediate Compound (G)

[0149] Intermediate Compound (F) in an amount of 9.0 g (31 mmoles), 8.7g (31 mmoles) of 1-phenylpyridinium bromide and 19.3 g (250 mmoles) ofammonium acetate were suspended into 27 ml of acetic acid and theresultant suspension was heated for 12 hours under the refluxingcondition. The reaction solution was then cooled at the roomtemperature. Toluene and water were added and the resultant mixture wasseparated into two layers. The organic layer was washed with a 10%aqueous solution of sodium hydroxide and a saturated aqueous solution ofsodium chloride, successively, and dried with anhydrous sodium sulfate.After the organic solvent was removed by distillation under a reducedpressure, 27 ml of ethanol was added. The formed crystals were separatedby filtration and washed with ethanol and 10.6 g (the yield: 88%) ofIntermediate Compound (G) was obtained.

[0150] (3) Synthesis of Compound (A72)

[0151] Intermediate Compound (G) in an amount of 3.5 g (9 mmoles), 1.7 g(10 mmoles) of carbazole, 0.09 g (0.5 mmoles) of copper iodide and 4.0 g(19 mmoles) of potassium phosphate were suspended into 18 ml of1,4-dioxane. To the obtained suspension, 0.5 ml (4 mmoles) oftrans-1,2-cyclohexanediamine was added. Under the atmosphere of argon,the resultant mixture was heated for 18 hours under the refluxingcondition. The reaction solution was then cooled at the roomtemperature. Methylene chloride and water were added and the resultantmixture was separated into two layers. The organic layer was washed witha 5% aqueous solution of hydrochloric acid and water, successively, anddried with anhydrous sodium sulfate. After the organic solvent wasremoved by distillation, 15 ml of ethyl acetate was added. The formedcrystals were separated by filtration and washed with ethyl acetate and3.5 g (the yield: 83%) of yellowish white crystals were obtained. It wasconfirmed by 90 MHz ¹H-NMR and FD-MS that the obtained crystals were thetarget substance (A72). The result of the measurement by FD-MS is shownin he following:

[0152] FD-MS caled. for C₃₅H₂₄N₂=472; found: m/z=472 (M⁺, 100)

[0153] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 12 (Synthesis of Compound (A73))

[0154] The route of synthesis of Compound (A73) is shown in thefollowing.

[0155] (1) Synthesis of Intermediate Compound (H)

[0156] In accordance with the same procedures as those conducted inSynthesis Example 2 (2) except that Intermediate Compound (F) obtainedin Synthesis Example 11 was used in place of Intermediate Compound (B),7.8 g (the yield: 61%) of Intermediate Compound (H) was obtained.

[0157] (2) Synthesis of Compound (A73)

[0158] In accordance with the same procedures as those conducted inSynthesis Example 11 (3) except that Intermediate Compound (H) was usedin place of Intermediate Compound (G), 3.3 g (the yield: 76%) ofyellowish white crystals were obtained. It was confirmed by 90 MHz¹H-NMR and FD-MS that the obtained crystals were the target substanceA73). The result of the measurement by FD-MS is shown in the following:

[0159] FD-MS calcd. for C₃₄H₂₃N₃=473; found: m/z=473 (M⁺, 100)

[0160] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 13 (Synthesis of Compound (A113))

[0161] The route of synthesis of Compound (A113) is shown in thefollowing.

[0162] In accordance with the same procedures as those conducted inSynthesis Example 11 (3) except that Intermediate Compound (C) obtainedin Synthesis Example 2 was used in place of Intermediate Compound (G),1.5 g (the yield: 50%) of yellowish white crystals were obtained. It wasconfirmed by 90 MHz ¹H-NMR and FD-MS that the obtained crystals were thetarget substance (A113). The result of the measurement by FD-MS is shownin the following:

[0163] FD-MS calcd. for C₃₃H₂₂N₄=474; found: m/z=474 (M⁺, 100)

[0164] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 14 (Synthesis of Compound (A98))

[0165] The route of synthesis of Compound (A98) is shown in thefollowing.

[0166] (1) Synthesis of Intermediate Compound (J)

[0167] In accordance with the same procedures as those conducted inSynthesis Example 2 (1) except that 3,5-dibromobenzaldehyde was used inplace of 4-bromobenzaldehyde and acetophenone was used in place of2-acetylpyridine, 19.2 g (the yield: 92%) of Intermediate Compound (J)was obtained.

[0168] (2) Synthesis of Intermediate Compound (K)

[0169] In accordance with the same procedures as those conducted inSynthesis Example 2 (2) except that Intermediate Compound (J) was usedin place of Intermediate Compound (B), 5.5 g (the yield: 45%) ofIntermediate Compound (K) was obtained.

[0170] (3) Synthesis of Compound (A98)

[0171] Intermediate Compound (K) in an amount of 3.0 g (6 mmoles), 2.3 g(14 mmoles) of carbazole, 0.12 g (0.6 mmoles) of copper iodide and 4.2 g(20 mmoles) of potassium phosphate were suspended into 21 ml of1,4-dioxane. To the obtained suspension, 0.8 ml (6 mmoles) oftrans-1,2-cyclohexanediamine was added. Under the atmosphere of argon,the resultant mixture was heated for 18 hours under the refluxingcondition. The reaction solution was then cooled at the roomtemperature. Methylene chloride and water were added and the resultantmixture was separated into two layers. The organic layer was washed withwater and dried with anhydrous sodium sulfate. After the organic solventwas removed by distillation under a reduced pressure, the residue ofdistillation was suspended into 21 ml of dioxane. To the obtainedsuspension, 0.12 g (0.6 mmoles) of copper iodide, 2.9 g (14 mmoles) ofpotassium phosphate and 0.8 ml (6mmoles) of trans-1,2-cyclohexanediaminewere added. Under the atmosphere of argon, the resultant mixture washeated for 18 hours under the refluxing condition. The reaction solutionwas then cooled at the room temperature. Methylene chloride and waterwere added and the resultant mixture was separated into two layers. Theorganic layer was washed with water and dried with anhydrous sodiumsulfate. After the organic solvent was removed by distillation under areduced pressure, 30 ml of ethyl acetate was added. The formed crystalswere separated by filtration and washed with ethyl acetate and 3.3 g(the yield: 80%) of yellowish white crystals were obtained. It wasconfirmed by 90 MHz ¹H-NMR and FD-MS that the obtained crystals were thetarget substance (A98). The result of the measurement by FD-MS is shownin the following:

[0172] FD-MS calcd. for C₄₆H₃₀N₄=638; found: m/z=638 (M⁺, 100)

[0173] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 15 (Synthesis of Compound (A105))

[0174] The route of synthesis of Compound (A105) is shown in thefollowing.

[0175] (1) Synthesis of Intermediate Compound (M)

[0176] In accordance with the same procedures as those conducted inSynthesis Example 11 (2) except that Intermediate Compound (J) obtainedin Synthesis Example 14 (1) was used in place of Intermediate Compound(F), 10.0 g (the yield: 88%) of Intermediate Compound (M) was obtained.

[0177] (2) Synthesis of Compound (A105)

[0178] In accordance with the same procedures as those conducted inSynthesis Example 14 (3) except that Intermediate Compound (M) was usedin place of Intermediate Compound (K), 2.9 g (the yield: 71%) ofyellowish white crystals were obtained. It was confirmed by 90 MHz¹H-NMR and FD-MS that the obtained crystals were the target substance(A105). The result of the measurement by FD-MS is shown in thefollowing:

[0179] FD-MS calcd. for C₄₇H₃₁N₃=637; found: m/z=637 (M⁺, 100)

[0180] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3.

SYNTHESIS EXAMPLE 16 (Synthesis of Compound (A108))

[0181] The route of synthesis of Compound (A108) is shown in thefollowing.

[0182] (1) Synthesis of Intermediate Compound (N)

[0183] 1,3,5-Tribromobenzene in an amount of 13.0 g (41 mmoles), 10.0 g(45 mmoles) of 3,5-diphenylpyrazole, 0.8 g (4 mmoles) of copper iodideand 11.9 g (86 mmoles) of potassium carbonate were suspended into 50 mlof 1,4-dioxane. To the obtained suspension, 4.9 ml (41 mmoles) oftrans-1,2-cyclohexanediamine was added. Under the atmosphere of argon,the resultant mixture was heated for 18 hours under the refluxingcondition. The reaction solution was then cooled at the roomtemperature. Methylene chloride and water were added and the resultantmixture was separated into two layers. The organic layer was washed withwater and dried with anhydrous sodium sulfate. After the organic solventwas removed by distillation under a reduced pressure, the remainingproduct was purified in accordance with the silica gel columnchromatography and 2.0 g (the yield: 11%) of Intermediate Compound (N)was obtained.

[0184] (2) Synthesis of Compound (A108)

[0185] Intermediate Compound (N) in an amount of 2.0 g (4 mmoles), 1.4 g(8 mmoles) of carbazole, 0.08 g (0.4 mmoles) of copper iodide and 2.9 g(14 mmoles) of potassium phosphate were suspended into 15 ml of1,4-dioxane. To the obtained suspension, 0.5 ml (4 mmoles) oftrans-1,2-cyclohexanediamine was added. Under the atmosphere of argon,the resultant mixture was heated for 18 hours under the refluxingcondition. The reaction solution was then cooled at the roomtemperature. Methylene chloride and water were added and the resultantmixture was separated into two layers. The organic layer was washed withwater and dried with anhydrous sodium sulfate. After the organic solventwas removed by distillation, the residue of distillation was suspendedinto 15 ml of 1,4-dioxane. To the obtained suspension, 0.08 g (0.4mmoles) of copper iodide, 2.9 g (14 mmoles) of potassium phosphate and0.5 ml (4 mmoles) of trans-1,2-cyclohexanediamine were added. Under theatmosphere of argon, the resultant mixture was heated for 14 hours underthe refluxing condition. The reaction solution was then cooled at theroom temperature. Methylene chloride and water were added and theresultant mixture was separated into two layers. The organic layer waswashed with water and dried with anhydrous sodium sulfate. After theorganic solvent was removed by distillation under a reduced pressure, 5ml of ethanol and 15 ml of ethyl acetate were added. The formed crystalswere separated by filtration and washed with a mixed solvent containingethyl acetate and ethanol in relative amounts by volume of 5:2 and 2.4 g(the yield: 87%) of yellowish white crystals were obtained. It wasconfirmed by 90 MHz ¹H—NMR and FD-MS that the obtained crystals were thetarget substance (A108). The result of the measurement by FD-MS is shownin the following:

[0186] FD-MS calcd. for C₄₅H₃₀N₄=626; found: m/z=626 (M⁺, 100)

[0187] The values of the energy gaps were obtained in accordance withthe same methods as those in Synthesis Example 1 and the results areshown in Table 3. TABLE 3 Singlet energy Triplet energy Com- gap gappound (eV) (eV) Synthesis Example 1 A5 3.2 2.7 Synthesis Example 2 A33.1 2.7 Synthesis Example 3 A26 3.1 2.6 Synthesis Example 4 A27 3.0 2.6Synthesis Example 5 A11 3.0 2.7 Synthesis Example 6 A9 3.1 2.5 SynthesisExample 9 B9 3.2 2.6 Synthesis Example 10 B11 3.2 2.7 Synthesis Example11 A72 3.5 2.8 Synthesis Example 12 A73 3.3 2.8 Synthesis Example 13A113 3.2 2.7 Synthesis Example 14 A98 3.5 2.9 Synthesis Example 15 A1053.4 2.9 Synthesis Example 16 A108 3.7 3.0

EXAMPLE 1

[0188] A glass substrate (manufactured by GEOMATEC Company) of 25 mm×75mm×1.1 mm thickness having an ITO transparent electrode was cleaned byapplication of ultrasonic wave in isopropyl alcohol for 5 minutes andthen by exposure to ozone generated by ultraviolet light for 30 minutes.The glass substrate having the transparent electrode lines which hadbeen cleaned was attached to a substrate holder of a vacuum vapordeposition apparatus. On the surface of the cleaned substrate at theside having the transparent electrode, a film ofN,N′-bis(N,N′-diphenyl-4-aminophenyl)-N,N′-diphenyl-4,4′-diamino-1,1′-biphenyl (a film of TPD232) having athickness of 60 nm was formed in a manner such that the formed filmcovered the transparent electrode. The formed film of TPD232 worked asthe hole injecting layer. On the formed film of TPD232, a film of4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (a film of NPD) having athickness of 20 nm was formed by vapor deposition. The formed film ofNPD worked as the hole transporting layer. On the formed film of NPD, afilm of the above Compound (A5) having a thickness of 40 nm was formedby vapor deposition. At the same time, Compound (D1) shown in thefollowing was vapor deposited in an amount such that the ratio of theamounts by weight of Compound (A5) to Compound (D1) was 40:3. Compound(D1) is a light emitting compound having a singlet energy as low as 2.79eV so that blue light is emitted. The formed mixed film of Compound (A5)and Compound (D1) worked as the light emitting layer. On the film formedabove, a film of BAlq shown in the following (Me means methyl group)having a thickness of 20 nm was formed. The film of BAlq worked as theelectron injecting layer. Thereafter, Li (the source of lithium:manufactured by SAES GETTERS Company) as the reducing dopant and Alqwere binary vapor deposited and an Alq:Li film having a thickness of 10nm was formed as the second electron injecting layer (the cathode). Onthe formed Alq:Li film, metallic aluminum was vapor deposited to form ametal cathode and an organic EL device was prepared.

[0189] When a direct current voltage of 5.0 V was applied to the organicEL device prepared above, blue light was emitted at a luminance of 150cd/m2 and an efficiency of the light emission of 6.3 cd/A. The chromaticcoordinates were (0.14, 0.16) and the purity of color was excellent.

EXAMPLES 2 to 8

[0190] In accordance with the same procedures as those conducted inExample 1 except that compounds shown in Table 4 were used in place ofCompound (A5), organic EL devices were prepared and the voltage of thedirect current, the luminance of the emitted light, the efficiency ofthe light emission, the color of the emitted light and the purity ofcolor were measured. The results are shown in Table 4.

COMPARATIVE EXAMPLE 1

[0191] In accordance with the same procedures as those conducted inExample 1 except that a conventional compound BCz shown in the followingwas used in place of Compound (A5), an organic EL device was preparedand the voltage of the direct current, the luminance of the emittedlight, the efficiency of the light emission, the color of the emittedlight and the purity of color were measured. The results are shown inTable 4.

COMPARATIVE EXAMPLE 2

[0192] In accordance with the same procedures as those conducted inExample 1 except that Compound (C2) shown in the following which isdescribed in Japanese Patent Application Laid-Open No. 2001-288462 wasused in place of Compound (A5), an organic EL device was prepared andthe voltage of the direct current, the luminance of the emitted light,the efficiency of the light emission, the color of the emitted light andthe purity of color were measured. The results are shown in Table 4.

TABLE 4 Organic Luminance Efficiency host material of emitted of lightColor of of light Voltage light emission emitted Chromatic emittinglayer (V) (cd/m²) (cd/A) light coordinates Example 1 A5 5.0 150 6.3 blue(0.14, 0.16) Example 2 A3 5.8 160 5.8 blue (0.15, 0.17) Example 3 A266.0 132 5.2 blue (0.14, 0.16) Example 4 A27 6.0 154 5.9 blue (0.14,0.16) Example 5 A11 5.2 180 6.3 blue (0.15, 0.17) Example 6 A9 6.2 1455.1 blue (0.15, 0.16) Example 7 B9 5.7 151 5.7 blue (0.15, 0.17) Example8 B11 5.0 181 6.9 blue (0.15, 0.17) Comparative BCz 8.5 70 2.4 blue(0.14, 0.16) Example 1 Comparative C2 6.5 65 2.6 blue (0.14, 0.16)Example 2

[0193] As shown in Table 4, in comparison with the organic EL devicesusing conventional compounds BCz and (C2) in Comparative Examples 1 and2, respectively, the organic EL devices using the compounds of thepresent invention could be driven at lower voltages and emitted bluelight in higher efficiencies. Since the energy gap of the compounds ofthe present invention is great, light emitting molecules having a greatenergy gap could be mixed into the light emitting layer and used for thelight emission.

EXAMPLE 9

[0194] A glass substrate (manufactured by GEOMATEC Company) of 25 mm×75mm×0.7 mm thickness having an ITO transparent electrode was cleaned byapplication of ultrasonic wave in isopropyl alcohol for 5 minutes andthen by exposure to ozone generated by ultraviolet light for 30 minutes.The glass substrate having the transparent electrode lines which hadbeen cleaned was attached to a substrate holder of a vacuum vapordeposition apparatus. On the surface of the cleaned substrate at theside having the transparent electrode, a film of copper phthalocyanineshown in the following (a film of CuPc) having a thickness of 10 nm wasformed in a manner such that the formed film covered the transparentelectrode. The formed film of CuPc worked as the hole injecting layer.On the formed film of CuPc, a film of1,1′-bis[4-N,N-di(p-tolyl)aminophenyl]cyclohexane (a film of TPAC)having a thickness of 30 nm was formed. The formed film of TPAC workedas the hole transporting layer. On the formed film of TPAC, a film ofthe above Compound (A72) having a thickness of 30 nm was formed by vapordeposition and the light emitting layer was formed. At the same time, Irbis[(4,6-difluorophenyl)pyridinato-N,C²′] picolinate (FIrpic shown inthe following) as the phosphorescent Ir metal complex was added. Theconcentration of FIrpic in the light emitting layer was set at 7% byweight. This layer worked as the light emitting layer. On the filmformed above, a film of Alq having a thickness of 30 nm was formed. Thefilm of Alq worked as the electron injecting layer. Thereafter, LiF asthe alkali metal halide was vapor deposited in an amount such that theformed film had a thickness of 0.2 nm and, then, aluminum was vapordeposited in an amount such that the formed film had a thickness of 150nm The formed film of Alq:Li film worked as the cathode. Thus, anorganic EL device was prepared.

[0195] When the obtained device was tested by passing the electriccurrent, bluish green light having a luminance of 89 cd/m² was emittedat a voltage of 6.6 V and a current density of 0.59 mA/cm². Thechromatic coordinates were (0.18, 0.39) and the efficiency of the lightemission was 14.98 cd/A.

EXAMPLES 10 to 12

[0196] In accordance with the same procedures as those conducted inExample 9 except that compounds shown in Table 5 were used in place ofCompound (A72), organic EL devices were prepared and the voltage of thedirect current, the current density, the luminance of the emitted light,the efficiency of the light emission, the color of the emitted light andthe purity of color were measured. The results are shown in Table 5.

COMPARATIVE EXAMPLE 3

[0197] In accordance with the same procedures as those conducted inExample 9 except that the conventional compound BCz was used in place ofCompound (A72), an organic EL device was prepared and the voltage of thedirect current, the current density, the luminance of the emitted light,the efficiency of the light emission, the color of the emitted light andthe purity of color were measured. The results are shown in Table 5.

COMPARATIVE EXAMPLE 4

[0198] In accordance with the same procedures as those conducted inComparative Example 3 except that4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD shown in thefollowing) was used for the hole transporting layer in place of thecompound TPAC and BAlq shown above was used for the electrontransporting layer in place of the compound Alq, an organic EL devicewas prepared and the voltage of the direct current, the current density,the luminance of the emitted light, the efficiency of the lightemission, the color of the emitted light and the purity of color weremeasured. The results are shown in Table 5.

TABLE 5 Organic Lumin- Effici- host ance of ency of material of Currentemitted light Color of Chromatic light emit- Voltage density lightemission emitted coordi- ting layer (V) (mA/cm²) (cd/m²) (cd/A) lightnates Example 9 A72 6.6 0.59 89 14.98 bluish (0.18, 0.39) green Example10 A98 6.4 0.54 86 15.89 bluish (0.18, 0.40) green Example 11 A105 6.90.84 99 11.76 bluish (0.17, 0.40) green Example 12 A73 6.0 1.00 99 9.91bluish (0.16, 0.39) green Comparative BCz 7.8 1.70 98 5.80 bluish (0.16,0.37) Example 3 green Comparative BCz 7.6 1.09 99 9.15 bluish (0.17,0.37) Example 4 green

[0199] As shown in Table 5, in comparison with the organic EL devicesusing the conventional compound BCz in Comparative Examples 3 and 4, theorganic EL devices using the compounds of the present invention could bedriven at a lower voltage and emit blue light at a higher efficiency.Since the energy gap of the compounds of the present invention is great,light emitting molecules having a great energy gap could be mixed intothe light emitting layer and used for the light emission.

[0200] Industrial Applicability

[0201] As described above in detail, by utilizing the material fororganic electroluminescence devices comprising the compound representedby general formula (1) or (2) of the present invention, the organicelectroluminescence device emitting blue light with a high efficiency oflight emission and an excellent purity of color can be obtained.Therefore, the organic electroluminescence device of the presentinvention is very useful as the light source for various electronicinstruments.

What is claimed is:
 1. A material for organic electroluminescencedevices which comprises a compound represented by following generalformula (1) or (2): (Cz—)_(n)A  (1) Cz(—A)_(m)  (2) wherein Czrepresents a substituted or unsubstituted arylcarbazolyl group orcarbazolylalkylene group, A represents a group represented by followinggeneral formula (A): (M)_(p)—(L)_(q)—(M′)_(r)  (A) wherein M and M′ eachindependently represent a heteroaromatic ring having 2 to 40 carbonatoms and nitrogen atom and forming a substituted or unsubstituted ring,M and M′ may represent a same ring or different rings, L represents asingle bond, a substituted or unsubstituted aryl group or arylene grouphaving 6 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having 5 to 30 carbon atoms or a substituted orunsubstituted heteroaromatic ring having 2 to 30 carbon atoms, prepresents an integer of 0 to 2, q represents an integer of 1 or 2, rrepresents an integer of 0 to 2, and p+r represents an integer of 1 orgreater; and n and m each represent an integer of 1 to
 3. 2. A materialfor organic electroluminescence devices according to claim 1, whereinn=1 in general formula (1) and p=1 and r=0 in general formula (A); ingeneral formula (1), Cz represents a substituted or unsubstitutedarylcarbazolyl group or carbazolylalkylene group; and in general formula(A), M represents a heterocyclic six-membered or seven-membered ringhaving 4 or 5 carbon atoms and nitrogen atom and forming a substitutedor unsubstituted ring, a heterocyclic five-membered ring having 2 to 4carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring, a heterocyclic ring having 8 to 11 carbon atoms andnitrogen atom and forming a substituted or unsubstituted ring or asubstituted or unsubstituted imidazopyridinyl ring, and L represents asubstituted or unsubstituted aryl group or arylene group having 6 to 30carbon atoms or a substituted or unsubstituted heteroaromatic ringhaving 2 to 30 carbon atoms.
 3. A material for organicelectroluminescence devices according to claim 1, wherein n=2 in generalformula (1) and p=1 and r=0 in general formula (A); in general formula(1), Cz represents a substituted or unsubstituted arylcarbazolyl groupor carbazolylalkylene group; and in general formula (A), M represents aheterocyclic six-membered or seven-membered ring having 4 or 5 carbonatoms and nitrogen atom and forming a substituted or unsubstituted ring,a heterocyclic five-membered ring having 2 to 4 carbon atoms andnitrogen atom and forming a substituted or unsubstituted ring, aheterocyclic ring having 8 to 11 carbon atoms and nitrogen atom andforming a substituted or unsubstituted ring or a substituted orunsubstituted imidazopyridinyl ring, and L represents a substituted orunsubstituted aryl group or arylene group having 6 to 30 carbon atoms ora substituted or unsubstituted heteroaromatic ring having 2 to 30 carbonatoms.
 4. A material for organic electroluminescence devices accordingto claim 1, wherein n=1 in general formula (1) and p=2 and r=0 ingeneral formula (A); in general formula (1), Cz represents a substitutedor unsubstituted arylcarbazolyl group or carbazolylalkylene group; andin general formula (A), M represents a heteroaromatic ring having 2 to40 carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring, and L represents a substituted or unsubstituted arylgroup or arylene group having 6 to 30 carbon atoms or a substituted orunsubstituted heteroaromatic ring having 2 to 30 carbon atoms.
 5. Amaterial for organic electroluminescence devices according to claim 1,wherein m=2 in general formula (2) and p=q=1 in general formula (A); ingeneral formula (2), Cz represents a substituted or unsubstitutedarylcarbazolyl group or carbazolylalkylene group; and in general formula(A), M and M′ each independently represent a heteroaromatic ring having2 to 40 carbon atoms and nitrogen atom and forming a substituted orunsubstituted ring, and M and M′ may represent a same ring or differentrings, and L represents a substituted or unsubstituted aryl group orarylene group having 6 to 30 carbon atoms, a substituted orunsubstituted cycloalkylene group having 5 to 30 carbon atoms or asubstituted or unsubstituted heteroaromatic ring having 2 to 30 carbonatoms.
 6. A material for organic electroluminescence devices accordingto claim 1, wherein Cz represents a substituted or unsubstitutedarylcarbazolyl group.
 7. A material for organic electroluminescencedevices according to claim 6, wherein Cz represents a substituted orunsubstituted phenylcarbazolyl group.
 8. A material for organicelectroluminescence devices according to claim 6, wherein an arylportion of the arylcarbazolyl group is substituted with carbazolylgroup.
 9. A material for organic electroluminescence devices accordingto claim 1, wherein a triplet energy gap of a compound represented bygeneral formula (1) or (2) is 2.5 to 3.3 eV.
 10. A material for organicelectroluminescence devices according to claim 1, wherein a singletenergy gap of a compound represented by general formula (1) or (2) is2.8 to 3.8 eV.
 11. An organic electroluminescence device comprising ananode, a cathode and an organic thin film layer comprising at least onelayer and disposed between the anode and the cathode, wherein at leastone layer in the organic thin film layer comprises a material fororganic electroluminescence devices described in claim
 1. 12. An organicelectroluminescence device comprising an anode, a cathode and an organicthin film layer comprising at least one layer and disposed between theanode and the cathode, wherein a light emitting layer comprises amaterial for organic electroluminescence devices described in claim 1.13. An organic electroluminescence device comprising an anode, a cathodeand an organic thin film layer comprising at least one layer anddisposed between the anode and the cathode, wherein an electrontransporting layer comprises a material for organic electroluminescencedevices described in claim
 1. 14. An organic electroluminescence devicecomprising an anode, a cathode and an organic thin film layer comprisingat least one layer disposed between the anode and the cathode, wherein ahole transporting layer comprises a material for organicelectroluminescence devices described in claim 1
 15. An organicelectroluminescence device according to claim 11, wherein the materialfor organic electroluminescence devices is an organic host material. 16.An organic electroluminescence device according to claim 11, whichcomprises an inorganic compound layer disposed between at least one ofthe electrodes and the organic thin film layer.
 17. An organicelectroluminescence device according to claim 11, which emits light by amultiplet excitation which is excitation to a triplet state or higher.18. An organic electroluminescence device according to claim 11, whichemits bluish light.